Display screen or portion thereof with a graphical user interface



The single FIGURE is a front view of a display screen or portion thereofwith a graphical user interface showing our new design.

The grayscale shading within the solid line shapes indicates contrastsin appearance. The outermost broken line showing the display screen orportion thereof and all other broken lines showing portions of thegraphical user interface are included for the purpose of illustratingportions of the article and form no part of the claimed design.

CLAIM We claim the ornamental design for a display screen or portionthereof with a graphical user interface, as shown and described.